frequenting, or only breeding here, or birds of passage, and 
Reptiles ; Mr. T. G. Ponton having undertaken to do the 
j Fishes of the neighbourhood. 
! Chemical and Photographic Section, April 12.— Dr. 
I W. B. Herapath, F.R.S., president, in the chair. It was 
proposed by Mr. Noble, the secretary, and resolved, that at 
[ future meetings one subject only should be formally 
j introt^uced by a member, as a paper or otherwise, and that 
I any member should be at liberty to bring forward a subject 
f(!>r discussion from one of the scientific periodicals. It was 
also agreed to suspend the meetings of the section in June, 
July, and August, and some conversation took place about 
taking photographs of geological strata for the projected 
work of the society. Mr. P. J. Worslej- read a paper on 
photographing in colour. He said that beginners in 
photography frequently obtained some amount of reproduc- 
tion of colour in their negatives, owing to a too great 
i exposure ; this, however, was the result of accident, and 
such negatives were useless for printing from, but Mr. 
Becquerel had discovered that pure chloride of silver, uncon- 
taminated by iodide or bromide, was sensitive to light in 
I such a way as to reproduce a very decided impression of a 
coloured spectrum, but the picture could not be fixed, and 
faded on exposure to light. M. Niepce de St. Victor had 
pursued the subject, and produced the most sensitive surface 
I by connecting a silver plate immersed in dilute hydrochloric 
acid with a voltaic battery ; a plate so prepared was very 
! sensitive, especially if heated to 30° c, or exposed to sunlight 
under red glass, and it could be used for several pictures 
successively. Subsequently he had been able to retard the 
fading by a mixture of chloride of lead and dextrine, and to 
take camera pictures with colours reproduced, which could 
be developed by heat after exposure. The president drew 
the attention of members to the inapplicability of the 
' magnesium light for portrait photography, its intensity 
causing a disagreeable expression in the sitter, and said that 
much of the wire now sold contained sodium, which rendered 
the) light much less actinic. Mr. P. J. VVorsley then gave 
the results of some experiments with dry plates prepared 
by various processes, showing that Fothergill's albumen 
process preserved the plates best, those prepared with grape 
sugar having completely spoiled in the 18 months they were 
kept. In no case could he obtain a picture without using 
nitr. silver as a developer. He also described a contrivance 
for obviating the over exposure of the sky, common in 
landscape photography. 
[ The meetings of the Botanical and Entomological sec- 
tions are suspended, and replaced by excursions.] 
F. ASHMEAD, ") 
S. H. S WAYNE, V Sectional Secretaries, 
A.NOBLE, J 
WM. LANT CARPENTER, 
Honorary Reporting Secretary. 
